Filter device and power converter

Abstract

Since inductance due to wiring to a Y capacitor is large, it is necessary to arrange the Y capacitor near a bus bar, and there is no degree of freedom in arranging the Y capacitor. Directions of currents flowing through a positive electrode side wiring 301 and a negative electrode side wiring 302 in a multi-core cable 300 are a direction 301a from a bus bar positive electrode terminal 114 toward the Y capacitor positive electrode terminal 201, and a direction 302b from a bus bar negative electrode terminal 115 toward the Y capacitor negative electrode terminal 202, respectively. On the other hand, a direction of a current flowing through a ground wiring 303 is a direction 302b from a Y capacitor ground terminal 203 toward a ground terminal 116. A magnetic flux generated by the currents flowing through the positive electrode side wiring 301 and the negative electrode side wiring 302 in the multi-core cable 300 and a magnetic flux generated by the current flowing through the ground wiring 303 in the multi-core cable 300 cancel each other out, and the inductance can be kept small.

The invention claimed is: 
     
       1. A filter device comprising:
 a Y capacitor; 
 a positive electrode side wiring that connects a positive electrode terminal of the Y capacitor to a positive electrode bus bar; 
 a negative electrode side wiring that connects a negative electrode terminal of the Y capacitor to a negative electrode bus bar; 
 a ground wiring that connects a ground terminal of the Y capacitor to a ground connection portion arranged near the positive electrode bus bar and the negative electrode bus bar; and 
 a cable bundling the positive electrode side wiring, the negative electrode side wiring, and the ground wiring, 
 wherein the Y capacitor is connected to the ground connection portion, the positive electrode bus bar, and the negative electrode bus bar via the cable. 
 
     
     
       2. The filter device according to  claim 1 , further comprising:
 a bus bar positive electrode connection portion that connects the positive electrode side wiring to the positive electrode bus bar; and 
 a bus bar negative electrode connection portion that connects the negative electrode side wiring to the negative electrode bus bar, 
 wherein the ground connection portion is arranged between the bus bar positive electrode connection portion and the bus bar negative electrode connection portion. 
 
     
     
       3. The filter device according to  claim 1 , wherein
 the cable includes a conductive shield layer that surrounds the positive electrode side wiring and the negative electrode side wiring, and 
 the shield layer constitutes the ground wiring. 
 
     
     
       4. The filter device according to  claim 1 , further comprising a housing that houses the filter device,
 wherein the ground connection portion is connected to the housing. 
 
     
     
       5. The filter device according to  claim 4 , further comprising
 a fixing portion that fixes the cable and brings the cable into contact with an inner wall of the housing. 
 
     
     
       6. A power converter including the filter device according to  claim 1 , the power converter comprising
 a circuit board on which a control circuit used in the power converter and the Y capacitor are mounted. 
 
     
     
       7. A filter device comprising:
 a Y capacitor; 
 a positive electrode side wiring that connects a positive electrode terminal of the Y capacitor to a bus bar positive electrode connection portion of a positive electrode bus bar; 
 a negative electrode side wiring that connects a negative electrode terminal of the Y capacitor to a bus bar negative electrode connection portion of a negative electrode bus bar; and 
 a ground wiring that connects a ground terminal of the Y capacitor to a ground connection portion connected to a housing that houses the filter device, 
 wherein the bus bar positive electrode connection portion, the bus bar negative electrode connection portion, and the ground connection portion are arranged near the positive electrode bus bar and the negative electrode bus bar, and the Y capacitor is connected to the bus bar positive electrode connection portion, the bus bar negative electrode connection portion, and the ground connection portion via a cable bundling the positive electrode side wiring, the negative electrode side wiring, and the ground wiring.